1. Field of the Invention
The present invention relates to a vibration generation device.
2. Description of the Related Art
A vibration generation device, a component converting electrical energy into mechanical vibrations using a principle of generation of electromagnetic force, is mounted in cellular phones, and the like, to be used for silently informing a user of call receipt.
Further, there is a growing demand for a multi-functional cellular phones as the market for portable electronic devices such as cellular phones, and the like, rapidly expands. Since demand for small, high-quality electronic device components is also increasing, demand for development of a vibration generation device having a new structure capable of remarkably improving quality while improving disadvantages of existing products has been increased.
As the release of cellular phones having large LCD screens rapidly increased in recent years, a vibration generation device for generating vibrations at the time of touch has been adopted due to the use of a touchscreen therein.
First, the vibration generation device used in a cellular phone in which a touchscreen is adopted is more frequently used than for generating vibrations at the time of call reception, and therefore, the operational lifespan of the vibrator needs to be increased. Second, the vibration generation device needs to have a rapid response speed, keeping pace with the speed of a user touching a touchscreen.
A cellular phone currently adopting a touchscreen uses a linear vibrator according to the demand for an extended lifespan and touch responsiveness.
The linear vibrator does not use a rotation principle of a motor but is vibrated by electromagnetic force having a resonance frequency determined by a size of an elastic member mounted in a vibrator and a weight body connected to the elastic member to generate vibrations.
As the size of the electronic device is reduced, the linear vibrator needs to be miniaturized. However, since the linear vibrator includes some essential components, limitations exist on the miniaturization of the linear vibrator. Therefore, a need exists for a linear vibrator having a new structure allowing for a dispositional relationship of components to be efficient.
Further, the linear vibrator generates vibration driving force by interaction between a magnet (a permanent magnet) and a coil (an electromagnet), but has degraded vibration performance due to interaction between the electromagnet and a magnetic material therearound during a repeated vibration process of the magnet included in the vibrator.